1. Field of the Invention
The present invention relates to a watch with a calendar mechanism including a first date indicator indicating the one place of a date and a second date indicator indicating the ten place of a date.
2. Description of the Related Art
The mechanical structure including the driving portion of a watch is generally referred to as the “movement.” What is obtained by mounting a dial and hands to the movement and putting it into a watch case to attain a complete whole is referred to as the “complete” of a watch. Of the two sides of a main plate constituting the base plate of a watch, the side where the glass of the watch case is provided, that is, the side where the dial exists, is referred to as the “back, side” or the “glass side” or the “dial side” of the movement. Of the two sides of the main plate, the side where the case back of the watch case exists, that is, the side opposite to the dial, is referred to as the “front side” or the “case back side” of the movement. A train wheel attached to the “front side” of the movement is referred to as the “front train wheel.” A train wheel attached to the “back side” of the movement is referred to as the “back train wheel.”
Generally speaking, in an analog watch, the “12 o'clock side” refers to the side where a scale corresponding to 12 o'clock of a dial is arranged. In an analog watch, the “12 o'clock direction” means a direction from the rotation center of an indicator hand toward the “12 o'clock side.” In an analog watch, the “3 o'clock side” refers to the side where a scale corresponding to 3 o'clock of the dial is arranged. In an analog watch, the “3 o'clock direction” means a direction from the rotation center of an indicator hand toward the “3 o'clock side.” In an analog watch, the “6 o'clock side” refers to the side where a scale corresponding to 6 o'clock of the dial is arranged. In an analog watch, the “6 o'clock direction” means a direction from the rotation center of an indicator hand toward “6 o'clock side”. In an analog watch, the “9 o'clock side” refers to the side where a scale corresponding to 9 o'clock of the dial is arranged. In an analog watch, the “9 o'clock direction” means a direction from the rotation center of the indicator hand toward the “9 o'clock side.” Further, in some cases, there are used terms implying sides where other scales of the dial are arranged as in the case of the “2 o'clock direction” and “2 o'clock side.”
In a first type of conventional watch with a calendar mechanism, there are provided a one-place rotary body (i.e., a first date indicator) on which there are arranged a dial having a large window and one number “1” and 31 numbers including 3 sets of numbers “1” through “9” and “0” and which is provided with four teeth, and a 10-place star plate (i.e., a second date indicator) which has four teeth and on which there are arranged the numbers “0,” “1,” “2,” and “3.” The 1-place rotary body (i.e., the first date indicator) directly rotates the 10-place rotary body (i.e., the second date indicator) (See, for example, Japanese Patent No. 3390021).
A second type of conventional watch with a calendar mechanism includes a first date plate indicating the 1 place of a date (i.e., a first date indicator), a second date plate indicating the 10 place of a date (i.e., a second date indicator), a date feeding wheel driving the first date plate, a feeding finger provided on the first date plate, an intermediate wheel driven by the feeding finger, a first jump control lever rotating the first date plate halfway through feeding to stop it at a stable position, and a second jump control lever rotating the second date plate halfway through feeding to stop it at a stable position. Arranged on the first date plate (i.e., the first date indicator) are 20 numbers including two sets of 20 numbers including the numbers “1” through “9” and “0” (See, for example, Patent Document JP-A-2000-314779).
A third type of conventional watch with a calendar mechanism comprises a first date indicator indicating the 1 place of a date, a first date jumper for setting the position in the rotating direction of the first date indicator, a second date indicator indicating the 10 place of a date, a second date jumper for setting the position in the rotating direction of the second date indicator, and a date intermediate wheel adapted to rotate based on the rotation of the first date indicator and capable of rotating the second date indicator. An indicator for displaying time information is operated by a step motor, and the first date indicator is operated by an ultrasonic motor (See, for example, Patent Document JP-A-2005-214836).
In a fourth type of conventional watch with a calendar mechanism, a figure-place-take-up tooth provided on a first date plate is connected to a second date plate via two date intermediate cogwheels. Date switching is effected by feeding the first date plate with 40 teeth by 2 teeth (See, for example, Patent Document JP-A-2000-292557).
A fifth type of conventional watch with a calendar mechanism is equipped with two moving bodies each carrying a number group arrangement. A second moving body is driven by a first moving body via a star retained by a jumper. A protruding element is arranged so as to prevent jumping from one tooth to a non-adjacent tooth of the star at the time of date change. The protruding element is displaced within a slider (See, for example, Patent Document JP-T-2006-522323).
The first type of conventional watch equipped with a calendar mechanism is equipped with a 1-place rotary member on which there are arranged the number “1” and 31 numbers including 3 sets of numbers of “1” through “9” and “0,” so that it is at the end of February, April, June, September, and November that the calendar mechanism needs correction at the end of a month. That is the calendar mechanism has to be corrected five times a year. However, in the first type of conventional watch with a calendar mechanism, the 1-place rotary member directly rotates the 10-place rotary member, so that it is impossible to arrange the 1-place rotary member and the 10-place rotary member such that they share the same rotation center. Thus, in designing the two rotary members, there are limitations regarding the position at which display of date is possible by the two rotary members.
In the second type of conventional watch with a calendar mechanism, there is a fear of the first date indicator being excessively rotated when correcting the date such that the first date indicator and the second date indicator become out of phase with each other. In this construction, there is a fear of a correct date display being impossible to achieve. To prevent this problem, it is necessary for the restraining force of the date jumper (i.e., the force of the second date jumper) to be large enough so as to be superior to the inertial force the first date indicator. Thus, in the third type of conventional watch with a calendar mechanism, it is necessary to increase the operational force applied to the train wheel for feeding the date indicators, resulting in an increase in the size and thickness of the watch.
The third type of conventional watch with a calendar mechanism includes a step motor and an ultrasonic motor, so that the date feeding mechanism is rather thick, and the motor driving circuit is complicated, with the IC size being rather large, which makes it necessary to provide a large number of electronic components.
In the fourth type of conventional watch with a calendar mechanism, there are arranged on the first date plate two sets of numbers of “0” and “1” through “9,” that is, 20 numbers. Thus, it is at the end of each month that the calendar mechanism requires correction. That is, the calendar mechanism has to be corrected twelve times a year.
In the fifth type of conventional watch with a calendar mechanism, the protruding element is formed integrally with the jumper. When the jumper follows the tooth portion when the user rotates the crown to correct the date display, the protruding element does not come into contact with the slider outer wall, and there is a fear of occurrence of excessive rotation (that is, the date display moving body carrying the number group arrangement is allowed to make excessive rotation due to the inertia during rotation, i.e., so-called “over-rotation”).